Heretofore, specific bioactive substances, etc. immobilized to an insoluble carrier have been widely used as adsorbents for affinity chromatography, therapeutic blood treatment agents, cell culturing equipment, antibiotic materials, analytical reagents, etc. This is an important field in which further broader applications may be expected in the future.
Polymers having reactive functional groups are usable for immobilization of bioactive substances, which are useful as materials for affinity chromatography adsorbents, therapeutic blood treatment agents, antibiotic materials, etc. As a polymer having reactive functional groups, derivatives of polystyrene are well known, but these are brittle polymers and therefore, there are limits to their molding. For example, they have the defect that they cannot be molded into hollow fibers or catheters.
Aromatic polysulfones are good in moldability, and therefore, are widely used as engineering plastics. Some are also used in the form of hollow fibers for applications for separating substances. If reactive functional groups are introduced to this polysulfone, the product can be used for immobilization of bioactive substances, the selective separation of substances, etc. and broader applications can be expected.
Reactions for introducing reactive functional groups to a polysulfone, however, are not much known. There are only a few examples, such as a sulfonating reaction (A. Noshay, L. M. Robeson, Journal of Applied Polymer Science, 20, 1885 (1976)) and a halomethylating reaction (Japanese Unexamined Patent Publication (Kokai) No. 51-8179, Japanese Unexamined Patent Publication (Kokai) No. 57-174104, Japanese Unexamined Patent Publication (Kokai) No. 62-42704, Japanese Unexamined Patent Publication (Kokai) No. 63-16204, A. Warshawsky et. al., Journal of Polymer Science, Part A, Polymer Chemistry, 28, 2885 (1990)), etc. There are only limited applications for the former (sulfonation), while the latter (halomethylation), which is expected to provide broad applications, has the defect of requiring the use of a dangerous, highly carcinogenic reagent (i.e., alkylhalomethyl ether). Further, the reactivity of the functional groups is too high and the chemical stability is poor. In addition, it is difficult to control the amount of the functional groups introduced.